1. The Field of the Invention
The present invention relates to a heat sink, and more particularly to a heat sink comprising a plurality circularly arranged fins extending from the inner sidewall of a hollow chassis towards the center of the hollow chassis with gaps there-between so that the width of the gaps gradually decreases from the inner sidewall to the center of the hollow chassis and a fan is used to generate air to increase the amount of air blowing through the wider gaps between the fins in order to increase the speed of heat dissipation.
2. Description of Related Art
The highly developed technology has made it possible to fabricate miniaturized electronic components for increasing the density of the electronic device and the operation efficiency thereof. In such a condition, if heat is not being dissipated properly, more and more heat generated by the operation of the electronic components gets accumulated within the electronic device causing over heating of the electronic device. Over heating may cause ionization and thermal stress to the electronic components and thereby adversely affecting the stability of the electronic components as well as shorten the service life of the electronic components. Therefore, heat dissipation of the heat generated by the operation of the electronic components cannot be ignored.
Nowadays, personal computers are widely used, and with the rapid advancement of the computer technology, newer and faster CPUs are being developed rapidly. The operation of high speed CPU with high efficiency usually generate more heat and because the surface area of the CPU is limited, heat of about 60 to 95° C. may seriously affect the operation of the CPU. Therefore, increasing the heat dissipation efficiency is very important.
Referring to FIG. 6, a conventional heat sink comprises a plurality of fins A and a substrate B. The fins A are positioned on the substrate B and are adapted for dissipating heat and the substrate B is stacked onto the heating object and is adapted for absorbing heat from the heating object. A through channel B1 is formed at a center portion of the substrate B to serve as the heat pipe. The substrate B absorbs heat from the heating object and transfers the heat to the fins A for dissipating heat to outside.
However, in the hollow through channel B1 at the center portion of the substrate B forming the heat pipe is too limited to provide sufficient surface area to efficiently facilitate liquid to gas transformation. In other words, the coolant in the steam state cannot be frozen promptly and thus the heat cannot be efficiently spread due to poor liquid to gas transformation, causing accumulation of heat on the substrate B and thereby adversely affect the stability and the decreasing service life of the heating object.
FIG. 7 discloses yet another conventional heat sink. The heat sink comprises a fan C and a panel D. The panel D is positioned on a surface of a heating object for dissipating heat generated by the heating object and the fan C is positioned above the panel D. The panel D is in a cylindrical shape and has a plurality of smooth spiral fins extending outwardly from a surface thereof for improving heat transfer to the surface of the fins. The rotation angle of the fins is designed to correspond to the rotation of the fan C for increasing heat dissipation. However, the fan C generates cool air and blows towards the panel D, the direction of cool air is directed by the smooth spiral fins which easily diverts the cool air away from the bottom of the panel D. Thus, the cool air cannot be blown to the bottom of the panel D to efficiently dissipate the heat there-from. Accordingly, resolving the defects of the conventional heat sinks described above is highly desirable and very important issue to the manufacturers in this field.